Direct current arc furnace hearth connection installation

Abstract

A direct current electric arc furnace hearth connection of the liquid-solid type is initially installed as a metal billet in an opening in a furnace construction, with water-containing refractory material rammed around the billet. When the material dries and with the furnace in operation, a melt in the furnace, which the billet must contact, with incidental melting of the inner end of the billet, cannot escape around the billet, the outer end of the billet being cooled and remaining solid to form an electrical connection for operation of the furnace. To accelerate drying of the rammed water-containing or moist refractory forming a lining around the billet, a hole is formed through the billet and a gas flame is burned at the hole on the inside end of the billet, while the resulting hot gases are sucked out of the billet's outside end, the flow of hot gases through the length of the billet, heating the billet to dry the rammed refractory material, particularly throughout its portion most adjacent to the furnace, more quickly than can be effected by conduction of heat through a solid billet not having a hole.

What is claimed is: 
     
       1. A method for drying a new hearth electrode installation of a DC electric arc furnace, the new installation comprising a metal billet extending through a wall portion of the furnace, the billet having an inside end which will be contacted by a melt in the furnace during operation of the furnace, and an outside end for an electrical connection, and at least slightly moist refractory surrounding the billet; said method comprising forming a hole lengthwise through the billet and passing hot gas through the hole to heat the billet until said refractory is substantially dried. 
     
     
       2. The method of claim 1 in which the hot gas is formed by gas burned at the inside end of the billet and suction is applied at the billet's outside end to suck the gas through the billet's hole.